// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_INTERPRETER_BLOCK_COVERAGE_BUILDER_H_
#define V8_INTERPRETER_BLOCK_COVERAGE_BUILDER_H_

#include "src/ast/ast-source-ranges.h"
#include "src/interpreter/bytecode-array-builder.h"

#include "src/zone/zone-containers.h"

namespace v8 {
namespace internal {
    namespace interpreter {

        // Used to generate IncBlockCounter bytecodes and the {source range, slot}
        // mapping for block coverage.
        class BlockCoverageBuilder final : public ZoneObject {
        public:
            BlockCoverageBuilder(Zone* zone, BytecodeArrayBuilder* builder,
                SourceRangeMap* source_range_map)
                : slots_(0, zone)
                , builder_(builder)
                , source_range_map_(source_range_map)
            {
                DCHECK_NOT_NULL(builder);
                DCHECK_NOT_NULL(source_range_map);
            }

            static constexpr int kNoCoverageArraySlot = -1;

            int AllocateBlockCoverageSlot(ZoneObject* node, SourceRangeKind kind)
            {
                AstNodeSourceRanges* ranges = source_range_map_->Find(node);
                if (ranges == nullptr)
                    return kNoCoverageArraySlot;

                SourceRange range = ranges->GetRange(kind);
                if (range.IsEmpty())
                    return kNoCoverageArraySlot;

                const int slot = static_cast<int>(slots_.size());
                slots_.emplace_back(range);
                return slot;
            }

            int AllocateNaryBlockCoverageSlot(NaryOperation* node, size_t index)
            {
                NaryOperationSourceRanges* ranges = static_cast<NaryOperationSourceRanges*>(source_range_map_->Find(node));
                if (ranges == nullptr)
                    return kNoCoverageArraySlot;

                SourceRange range = ranges->GetRangeAtIndex(index);
                if (range.IsEmpty())
                    return kNoCoverageArraySlot;

                const int slot = static_cast<int>(slots_.size());
                slots_.emplace_back(range);
                return slot;
            }

            void IncrementBlockCounter(int coverage_array_slot)
            {
                if (coverage_array_slot == kNoCoverageArraySlot)
                    return;
                builder_->IncBlockCounter(coverage_array_slot);
            }

            void IncrementBlockCounter(ZoneObject* node, SourceRangeKind kind)
            {
                int slot = AllocateBlockCoverageSlot(node, kind);
                IncrementBlockCounter(slot);
            }

            const ZoneVector<SourceRange>& slots() const { return slots_; }

        private:
            // Contains source range information for allocated block coverage counter
            // slots. Slot i covers range slots_[i].
            ZoneVector<SourceRange> slots_;
            BytecodeArrayBuilder* builder_;
            SourceRangeMap* source_range_map_;
        };

    } // namespace interpreter
} // namespace internal
} // namespace v8

#endif // V8_INTERPRETER_BLOCK_COVERAGE_BUILDER_H_
